The present invention relates to a shaft seal. More particularly, it relates to a shaft seal for a rotatable shaft surrounded by a substantially rigid structural element.
Shaft seals have been proposed in the art, wherein when the shaft rotates with a great number of revolutions or the shaft drily rotate in sealing lips, so-called "stick-slip" effect takes place, as a result of which effect the sealing lips are radially displaced under the action of radial vibrations. These vibrations are connected with an unpleasant whistling sound, and in certain cases can progressively increase so that the sealing lips or the shaft seal will be destroyed when inherent damping capability of an element which urges the sealing lips toward the shaft cannot longer limit the above-mentioned vibrations.